Thursday, 27 July 2017

M16: the pillars of creation

M16, otherwise known as the Eagle Nebula, is another one of summer's highlights. Though less bright than nearby M17, it only takes a pair of binoculars to discover this very young star cluster surrounded by their maternal gas cloud. The nebula became especially famous when astronomers discovered active star formation for the first time, right in its central region. There lie the so-called "Pillars of Creation" which are obvious on long-exposure photographs but extremely difficult to make out visually. When I come to think of it, I've never seen them through a telescope before, until I got my new binos that is. These "pillars" are in fact long and very dense clouds of gas and matter that are creating hundreds of new stars as we speak. I was able to make out three "fingers" on top of them, which in reality are at least four light-years long! Within these "fingers", the Hubble space telescope discovered hundreds of globules and proto-stars. A theory goes that a nearby supernova explosion, which happened some 7,000 years ago, has blown away most of the surrounding matter and that the "pillars" are currently the only thing left. Given that the Eagle Nebula lies between 6,500 and 7,000 light-years away, the "pillars" have probably dissipated completely as well by now; it's only that the light of that event hasn't reached us yet. What we can already see very clearly is that the intense radiation of the hot, newborn stars is eroding the nebula very quickly. The "fingers", for example, are being torn apart by the stellar winds of the bright little star in the middle of them. Eventually the whole nebula will disappear, as will the cluster of young stars that has formed within it.